DE 199 43 294 A1 discloses a fluid supply system of an internal combustion engine having a filter device and a cooler upstream of said filter device that can be switched on in the fluid circuit in a temperature-dependent manner. In a lower and an upper temperature range, at least a predominant part of the volume flow in this case passes through the cooler, while in a middle temperature range located therebetween, at best a non-predominant part of the volume flow passes through the cooler. In this way, it should be possible for the temperature of the fluid to be optimally adjusted to operating conditions of the internal combustion engine.
An automatic transmission for vehicles with a hydrodynamic converter is known from DE 199 02 408 A1, said converter being supplied with oil by a compressed oil pump via a main pressure valve, wherein a converter safety valve restricts the oil pressure upstream of the converter and a lubricating oil line branches off from the oil supply line, which lubricating oil line contains a lubricating valve and wherein an oil cooler is provided in addition. This oil cooler is arranged in an oil line between the main pressure valve and the branch line of the lubricating oil line and has a bypass, the flow rate whereof is controlled or regulated.
FR 2 655 702 A1 discloses a fluid supply system with a component, wherein a bypass valve with a valve body arranged in a control channel is provided which is adjustable at least between a first position and a second position and which blocks a fluid channel to the component in the first position and a bypass channel bypassing the component in the second position. The valve body itself divides the control channel into a first chamber and a second chamber and, moreover, has a leakage opening which connects the first chamber to the second chamber. A spring element which pretensions the valve body in its second position is arranged in the second chamber in this case. Moreover, the second chamber is connected via a leakage channel to a fluid reservoir, wherein a switchable valve for the at least partial opening and closing of the leakage channel is arranged in this leakage channel. At least one detection device is also provided, in addition, which detects a property of the fluid and transmits it to a control device which is in turn configured in such a manner that it closes the valve when a predefined property is reached and thereby blocks the leakage channel.
A further fluid supply system with a component is known from WO 2015/172792 A1.
A fluid supply system with a control channel and a bypass valve arranged therein is known from JP S62-248812 A. The bypass valve has a valve body which is adjustable at least between a first and a second position and which in the first position cuts off a fluid channel to the component and in the second position cuts off a bypass channel bypassing the component. The valve body in this case divides the control channel into a first and second chamber and, in addition, has a leakage opening which connects the first chamber to the second chamber.
Fluid supply systems in internal combustion engines, for example oil filter modules, are normally fitted with a cooler to protect the fluid, in particular the oil, from damage due to high temperatures during running. In the cold state, however, the pressure loss of the cold fluid rises due to the altered flow properties, which is why a bypass valve fitted with an expansion element is normally provided which, when a predefined temperature is fallen short of or has not yet been reached, directs a fluid flow past the cooler and only conducts said fluid flow through the cooler, for example the oil cooler, when the predefined temperature has been reached. This means that corresponding lubrication of an internal combustion engine or bearing points, for example, should still be achieved even in the cold state.
As an alternative to the aforementioned expansion elements, so-called bi-metal or FGL switches can also be used, wherein all temperature-dependent bypass circuits are comparatively complex and expensive due to the switches used, for example expansion elements, and, moreover, have a certain inertia which means that rapid switching becomes impossible. In addition, bypass valves with so-called wax expansion elements, in particular, usually require a temperature difference of at least 10 Kelvin in order to achieve the working stroke.